1. Field of the Invention
The present invention relates to a method for producing a long circularly polarizing plate and to a long circularly polarizing plate.
2. Description of the Related Art
A liquid crystal display device is known having a wide-band circularly polarizing plate in which a polarizing film made of polyvinyl alcohol dyed with iodine, a half-wave plate, and quarter-wave plate are stacked.
In such a wide-band circularly polarizing plate, it is necessary to stack these by shifting the angle formed by the slow axis of the half-wave plate and the absorption axis of the polarizing film and the angle formed by the slow axis of the quarter-wave plate and the absorption axis of the polarizing film each by 15° or 75°, making it difficult to fabricate the circularly polarizing plate by roll-to-roll bonding. On the other hand, thickness reduction of the display device is strongly demanded and, for this reason, thickness reduction or the circularly polarizing plate is also demanded.
JP-A-2006-337892 discloses a circularly polarizing plate having a thickness of 130 to 370 μm in which a reverse wavelength dispersive film and a polarizing plate obtained by applying a dichroic dye are stacked on a retardation layer.
However, in the circularly polarizing plate disclosed in JP-A-2006-337892, the two films are stacked via a pressure-sensitive adhesive agent or an adhesive agent so that the absorption axis of the polarizing plate and the slow axis of the retardation plate may form an angle of 45°, so that the thickness of the circularly polarizing plate and the convenience of the production steps have not been sufficient.